Stunning Purple and Aurora Borealis Vintage Necklace

My daughter has a Necklace just like this with red stones instead of purple, hers is marked Coro. The mark on this one does not show due to the extremely gold plating. Purchased in the late 70's.

The quality is very indicative of Coro. Very unusual piece, very well made. Measures 16 inches long but can be made much shorter with the extender.